A number of ADSL customers with Internet service providers (ISPs) that use Internet Solutions as their ADSL supplier reported slow or no connectivity the weekend of 13 – 15 September 2013.
Internet Solutions (IS) has confirmed the downtime, with a spokesperson explaining that about an eighth of their digital subscriber line (DSL) address space was affected.
“Users affected would have experienced slow connectivity with a larger impact on local traffic,” Internet Solutions said.
The problem started on Friday evening and was only resolved at 10:45 on Sunday, 15 September 2013, the spokesperson said.
Asked what caused the problem, IS said, “Due to a technical error another [Autonomous System] advertised a part of the Internet Solutions address space to the Internet.”
An Autonomous System (AS), according to RFC 1930, is “a connected group of one or more IP prefixes run by one or more network operators which has a single and clearly defined routing policy.”
This means that another network advertised (using Border Gateway Protocol) that traffic destined for Internet Solutions’ network should be routed to it instead.
An ISP that uses Internet Solutions as its upstream service provider expressed concern to MyBroadband that a rival ISP could do this maliciously to remove a competitor off the Internet.
However, Internet Solutions said that there didn’t appear to be malicious intent on the part of the AS at fault.
“This was confirmed to be a technical error by the other ISP and a permanent fix has been put in on their side,” Internet Solutions said.
Asked what safeguards can be put in place to prevent a third party from bringing down someone else’s whole network, IS said that this is an inherent risk on the Internet.
“The Internet still relies heavily on co-operation between ISPs,” IS said. “There is always some risk of an error, especially if the error is on the part of a generally trusted and widely connected ISP.”